Limnetica, 29 (2): x-xx (2010) Limnetica, 29 (2): 393-406 (2010). DOI: 10.23818/limn.29.33 c Asociacion´ Iberica´ de Limnolog´a, Madrid. Spain. ISSN: 0213-8409 Estado ecologico´ del r´oOja (cuenca del Ebro, La Rioja, Espana),˜ mediante indicadores de macroinvertebrados Mar´a Valladolid1,∗, Mercedes Arauzo2 yJuanJoseMart´ ´nez-Bastida2 1 Dpto. Biodiversidad y Biolog´a Evolutiva, Museo Nacional de Ciencias Naturales (CSIC), c/JoseGuti´ errez´ Abascal, 2. 28006 Madrid. Fax: 34 91 564 50 78. 2 Dpto. Contaminacion´ Ambiental. Instituto de Ciencias Agrarias. Centro de Ciencias Medioambientales (CSIC), c/ Serrano 115 dpdo., 28006 Madrid, Spain. Fax: 34 91 564 08 00. e-mails:
[email protected],
[email protected] ∗ Autor responsable de la correspondencia:
[email protected] 2 Recibido: 23/2/10 Aceptado: 21/7/10 ABSTRACT Ecological status of the Oja River (Ebro Basin, La Rioja, Spain) based on macroinvertebrate indexes This work provides results about the water quality of the Oja or Glera River (Oja-Tiron´ basin) during the years 2003-2007, as well as information from the historical data taken from previous basin reports (2004 report, that includes data from 1994 to 2004 and 2007 report). Seven sampling points have been selected, distributed between the three typologies dened in the Oja River: in ecotype 11, Siliceous Mediterranean mountain river, 3 points; in ecotype 26, Humid calcareous mountain river,1 point and in ecotype 12, Mediterranean calcareous mountain rivers, 3 points. Several macro invertebrate indexes (IBMWP, IASPT, NFAM, NFPLE and EPT) and their ecological quality ratios (EQR) were calculated for each point.